Experiments are proposed using neuropsychological, behavioral, and electrophysiological measures to investigate deficits in specific stages of the reading process in dyslexic children. Groups of normal readers and dyslexics will be defined on the basis of their performance on a neuropsychological test battery focussed on reading skills and the differentiation of dyslexic subgroups. Additional neuropsychological measures will be used to supplement the information obtained from the electrophysiological measures. Event-related potentials will be recorded in a series of tasks in which stages of processing are varied systematically. Non-linguistic and linguistic stimuli will be compared, as will as will auditory and visual modes of presentation. Four experiments are proposed to investigate the following variables: 1) linguistic (phonemes) vs. non-linguistic (tones) auditory stimuli under varying degrees of task difficulty, 2) visual vs. auditory semantic classification of words, 3) grapheme-to-phoneme conversion, and 4) discrimination of stimulus order (sequencing) during sequential and simultaneous presentations. The long-term objectives are to identify the stages of processing at which dyslexic readers are deficient. Topographical analyses of the event-related potentials will assist in the distinction of the deficient processing stages underlying reading difficulties.